Question: Solve for $y$ : $30 + y = 6$
Subtract $30$ from both sides: $ \begin{eqnarray} \\ 30 + y &=& 6 \\ \\ {-30} && {-30} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{30 + y} &\hphantom{=}& \hphantom{6} \\ y &=& 6 {- 30} \\ \end{eqnarray} $ Simplify. $ y = -24$